Older drivers who have worse spatial orientation ability experience greater difficulty when making turns across oncoming traffic, according to new research from the University of East Anglia (UEA).
Spatial orientation skills are the combination of skills that enable us to mentally determine our position, or the position of our vehicle and other vehicles, relative to the environment.
Lead author Sol Morrissey, a PhD researcher at UEA's Norwich Medical School, said: "Driving safety is typically reduced in older adults due to changes that take place during the ageing process, but little is known about how changes in the brain influence driving behaviour.
"This study shows that older adults with worse spatial orientation ability are less likely to drive frequently, and they report greater difficulty during driving.
"Importantly, we establish that having worse spatial orientation ability is associated with greater difficulty when making turns across oncoming traffic – which is a significant risk factor for fatal road traffic accidents.
"Driving safety assessments may therefore look to implement spatial orientation tests in the future."
A total of 804 older adults were recruited between February 2021 and August 2021 to complete the study, with an average of 71.05 years.
Participants needed to be 65 or older, hold a current driving licence, and be a regular motorist, driving at least once per week.
Those recruited then completed online questionnaires related to their demographic information, health status, driving history, driving habits, road traffic incident history, spatial memory, and navigation ability.
Following this, participants completed a set of neuropsychological tests that assessed for cognitive performance across a variety of areas.
The results showed that driving behaviour difficulty and avoiding difficult situations is associated with worse spatial orientation ability within healthy ageing.
The study also replicated previous findings that processing speed is a key area affecting driving behaviour in ageing.
Spatial orientation has clear relevance to driving behaviour, as deficits will lead to increased difficulty in judging the position of the vehicle in relation to the surrounding environment. Furthermore, spatial orientation was the only cognitive domain demonstrating a significant effect on driving behaviour across the older age spectrum.
Older adults are overrepresented particularly in intersection crashes that involve multiple vehicles, and therefore orientation deficits are a key individual risk factor for road collisions involving turns across oncoming traffic.
Spatial orientation performance significantly predicted driving difficulty and frequency. Experiencing more driving difficulty was associated with worse spatial orientation, processing speed, and episodic memory performance.
Similarly, avoiding challenging driving situations was associated with worse spatial orientation and episodic memory.
Prof Michael Hornberger, of Norwich Medical School, said: "The research showed that deficits in spatial orientation are a robust indicator of driving performance in older age.
"This should be considered in future ageing driving assessments, as it has clear relevance for road safety within the ageing population.
"The proportion of older drivers on the road is projected to increase significantly in future years.
"Driving is of great importance in maintaining independence in older age, but it is also well established that age-related physiological changes and health conditions in older age increase the risk for driving collisions, and that these incidents are more likely to be fatal than for younger drivers."
To date, research on the impact of ageing on driving performance has largely focused on physical and sensory function.
By contrast, cognitive changes, which are known to be critical for driving performance, have been much less explored in healthy ageing populations.
Most large-scale cognitive driving studies have only employed cognitive screening tests and even those in-depth studies have not considered how spatial orientation/navigation, a critical process for everyday mobility, impacts driving performance in ageing.
This latest research provides large-scale normative data of cognitive functioning within healthy older adults using online cognitive assessments.
Prof Hornberger added: "Online assessment batteries are particularly relevant for screening for changes in driving fitness over time, as they can be employed more conveniently, are more resource-efficient, and offer more precise measurements than in-person psychometric tests."
The researchers also said the role of spatial orientation in predicting driving difficulty provides a potential explanation as to why road safety is reduced for motorists who have Mild Cognitive Impairment (MCI) and Alzheimer's disease.
The researchers note some limitations to the study. Firstly, driving behaviours were self-reported by participants, and therefore may be subject to inaccuracy and/or bias.
Secondly, they were unable to investigate the environment in which participants typically drive, for example comparing rural and urban areas, and how these could have a significant impact on mobility requirements, type of driving, and cognitive functioning.
Future research may look to employ naturalistic driving measurements, such as via GPS location devices, to provide objective measures of driving behaviour and performance.
Further investigation should also be conducted into how driving behaviour changes relates to trajectories in cognitive functioning over time, which will provide key information as to how often fitness to drive assessments should be implemented and how both driving behaviour and cognitive assessments can be monitored.
The research was led by the University of East Anglia, in partnership with the University of Exeter, the University of Leeds, the Norfolk and Norwich University Hospitals NHS Foundation Trust and the MemCheck Memory Clinic at Chester Wellness Centre.
The study was funded by the UK Department for Transport and supported by the National Institute for Health and Care Research (NIHR) Applied Research Collaboration East of England (NIHR ARC EoE) at Cambridge and Peterborough NHS Foundation Trust.
The views expressed are those of the authors and not necessarily those of the NIHR or the Department of Health and Social Care (UK) or the Department for Transport.
Sol Morrissey's studentship is jointly funded by the Faculty of Medicine & Health Sciences, University of East Anglia, and the Earle and Stuart Charitable Trust.
'The impact of spatial orientation changes on driving behaviour in healthy ageing' is published in the Journal of Gerontology: Psychological Sciences.
